An electronic device, such as a camera or a smartwatch, may include interior space that is curved or irregular in some way. However, batteries (or individual cells of batteries) used in such a device often have a square or rectangular shape. Using a square or rectangular-shaped battery in such a device may result in the inefficient use of the available interior space within the device. That is, the energy capacity of the battery may be small due to the battery's shape not conforming to the interior space of the device.